Air handling lighting fixture

ABSTRACT

An encased lighting fixture structure incorporates fluorescent light tubes and also defines air passage means on opposite sides having first ends terminating in opposite side openings and their other ends opening out in elongated bottom slots adjacent to the opposite sides and substantially coextensive therewith. Each of the air passage means includes an elongated damper member of tapered configuration to define with the passage an air passage of increasing cross-sectional area towards the end of the member so that air passing through is distributed from the slot with a substantially uniform air velocity profile. The physical dimensioning of the casing structure, air passage means, and damper members is such as to provide sufficient air volume flow with a minimum height dimension.

United States Patent Garrett et al.

[ Feb. 22, 1972 [54] AIR HANDLING LIGHTING FIXTURE [72] inventors: Robert E. Garrett; Leon D. Dame, both of 1544 West 8th Street, Los Angeles, Calif. 90017 22 Filed: Feb. 24, 1970 21 Appl.No.: 13,645

Primary ExaminerRichard C. Queisser Assistant Examiner-Arthur E. Korkosz Attorney-Pastoriza & Kelly [57] ABSTRACT An encased lighting fixture structure incorporates fluorescent light tubes and also defines air passage means on opposite sides having first ends terminating in opposite side openings and their other ends opening out in elongated bottom slots adjacent to the opposite sides and substantially coextensive therewith. Each of the air passage means includes an elongated damper member of tapered configuration to define with the passage an air passage of increasing cross-sectional area towards the end of the member so that air passing through is distributed from the slot with a substantially uniform air velocity profile. The physical dimensioning of the casing structure, air passage means, and damper members is such as to provide sufficient air volume flow with a minimum height dimension.

7 Claims, 4 Drawing Figures PATENTEDFEB 22 I972 on H mm N ERE W M T m A a T E w A B. M R

N mm M RLQ FIG.4

ll SZ AIR HANDLING LIGHTING FIXTURE This invention relates generally to combined lighting and airflow fixtures and more particularly, to an improved air handling lighting fixture for mounting within the ceiling cavity of a suspended ceiling installation in commercial buildings.

BACKGROUND OF THE INVENTION Most present day commercial buildings include air-conditioning systems. Ducting for these systems is normally located in the ceiling cavity area with suitable branch air inlet and outlet openings extending from the ducting to suitable inlet and outlet air openings in the ceilings of the various rooms or offices. In modern construction, it is also common practice to provide substantially flush mounted lighting fixtures in such rooms, the normal bulkiness of such fixtures being accommodated in the cavity area above the ceiling and below the next adjacent floor in a multistory construction.

To simplify construction techniques and eliminate as many openings as possible in the ceilings of the various rooms or offices, several different types of combination lighting fixture and air handling passages have been proposed. These units generally include a casing structure incorporating suitable lights and also defining air passages for connection to ducting in the ceiling. All such units as have presently been designed, however, are considerably more bulky than a standard lighting fixture if they are to be capable of handling the required volume flow of air. As a result, such fixtures will not readily fit within the cavity area particularly with respect to the depth or vertical distance between the ceiling and next adjacent floor.

Further problems arise in that relatively large cross-sectional area air inlet and outlet openings are required to handle the airflow and these requirements add to the bulkiness of the device and require larger ceiling openings than would otherwise be required. If an attempt is made to change the geometry of the inlet and outlet air openings; for example elongation of the same in order that a given cross-sectional area may be comfortably accommodated with the lighting fixture, restricted air passage portions can cause undesirable whistling effects. These effects result directly from the increased velocity of airflow through restricted openings.

Other problems which must be considered relate to architectural considerations from the aesthetic standpoint, ease of installation, and general overall expense involved in providing such combined units.

BRIEF DESCRIPTION OF THE PRESENT INVENTION The present invention is directed towards the provision of an air handling lighting fixture combination so designed as to overcome the major aforementioned problems.

More particularly, the air handling lighting fixture of the present invention is so designed as to provide a very compact configuration particularly in its height dimension so that it is readily receivable within conventional ceiling cavity areas in commercial buildings. In spite of this compact construction, the fixture is so designed as to be capable of handling full airflow requirements.

Briefly, the air handling lighting fixture of the invention comprises an open bottom casing incorporating fluorescent light tubes, the casing also including air passage means having one end terminating at a side opening in the casing and its other end opening out in an elongated slot defined by a marginal bottom portion of the casing. This slot is substantially coextensive with an entire side dimension of the casing so that its total cross-sectional area is positioned to accommodate desired airflow volume. Within the air passage means there is provided an elongated damper member of tapered configuration to define an increased area air passage in the passage means at points further from the side openings than at points closer to the side opening so that air passing through the air passage is distributed from the slot with a substantially uniform air velocity profile. By this arrangement, maximum airflow volume can be handled with minimum risk of whistling sounds and with the additional advantage of minimizing dimensions of the air openings in given directions.

In the preferred embodiment, the casing structure itself is designed for mounting directly on T-bar ceiling installations within the ceiling cavity area there being provided at least two of the air passage means incorporated in opposite sides of the casing structure. One of the air passage means may serve as an inlet air opening to a room and the other as the outlet air opening. Alternatively, where additional lighting fixtures are provided in the room or ofiice, both passages may serve as air inlets to the room and both passages in another fixture in the room serve as air outlet passages.

BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the invention will be had by referring to the accompanying drawings, in which:

FIG. 1 is a perspective view of the top side of an air handling lighting fixture in accord with the present invention;

FIG. 2 is a reduced scale bottom cross-sectional view taken in the direction of the arrows 2-2 of the fixture of FIG. 1;

FIG. 3 is an enlarged fragmentary cross section taken in the direction of arrows 33 of the fixture of FIG. 1; and,

FIG. 4 is a cross section taken in the direction of the arrows 4-4 of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, there is shown an open bottom casing structure 10 having a marginal flange 11 designed for seating on appropriate portions of a T-bar ceiling installation indicated in phantom lines at 12. Airflow inlet and outlet openings 13 and 14 are provided in central positions on opposite sides of the casing 10 as shown. These openings are purposely elongated in cross section as shown in order to minimize the overall height dimension of the casing structure and yet accommodate a given airflow. As shown in FIG. 1, the inlet and outlet openings 13 and 14 are connected to suitable air handling ceiling ducts 15 and 16 respectively. The end portions of these ducts may be flattened or appropriately modified in shape as indicated at 17 and 18 for direct connection to the inlet and outlet of the fixture.

Referring to the bottom plan cross section on reduced scale as shown in FIG. 2, it will be noted that there are provided elongated bottom air inlet and outlet slots 19 and 20 adjacent to the opposite sides accommodating the inlet and outlet openings 13 and 14. Between these marginal bottom side portions within the casing 10 there are incorporated a plurality of U-shaped fluorescent lighting tubes 21, 22, 23, and 24. Other shaped fluorescent lighting tubes may be provided for other types of easing geometry. In the particular example chosen for illustrative purposes which constitutes a substantially squareshaped configuration, the U-shaped type of fluorescent tube is best suited and provides a fairly uniform light distribution over the bottom area.

Normally, there would be provided a diffusion glass or plastic cover on the bottom of the fixture but this cover has been omitted in FIG. 2 in order to illustrate the lighting components clearly. Further, from an architectural standpoint, the finishing bottom cover would preferably include marginal stripes to simulate openings similar to the elongated slot openings 19 and 20 and thus provide a symmetrically appearing configuration.

Suitable ballasts for the lighting fixtures are indicated by dotted lines at 25 and 26 and it will be noted that these ballasts are disposed close to the elongated air slots 19 and 20.

Referring now to the enlarged scale fragmentary cross section of FIG. 3, details of the air handling portion of the fixture will become evident. It should be understood that the opposite sides incorporating the inlet and outlet openings and the slot openings are identical in construction and therefore description of one will suffice for both.

With particular reference to FIG. 3, the inlet opening 13 communicates with the bottom marginal elongated slot air opening 19 through an air passage means 27 formed by the sidewalls of the casing. This air passage means includes a damper member 28 which may be pivoted to a side of the passage means as at 29. A control rod 30 is coupled to the damper member 28 and passes through a guide flange 31 to terminate in a handle 32 enabling manual swinging movement of the damper. The arrangement is such that the damper 28 may be swung from an open position wherein it is essentially parallel to airflow through the passage means 27 to a position substantially normal to such airflow to minimize the airflow as indicated by the dotted lines.

In FIG. 3, it will be noted that the ballast 25 is in thermally conductive contact with metallic portions of the casing 10, these portions in turn being thermally connected to at least a sidewall portion of the passage 27 so that cooling of the ballast is effected by airflow through the passage.

Referring to FIG. 4, the geometry of the damper member 28 in relation to the air passage 27 will be clear. As indicated, the damper member is elongated in the direction of the slot 19 and tapers in cross-sectional area from its central portion towards its end portions. This tapering is such as to define in the air passage means an elongated air passage increasing in cross section towards its ends. The increase is indicated by the letters S1 and S2 successively disposed at greater distances from the central portion. Air centrally admitted through the inlet 13 is thus distributed to pass out of the associated slot 19 with a substantially uniform velocity profile. Similarly, in the case of the air outlet opening 14 and outlet slot described in FIG. 2, air passed up through the slot and associated outlet is uniformly received and collimated.

The unifonn air velocity profile from the slot is a consequence of the increased air passage space towards the ends of the slot where the pressure is less than at the central area adjacent to the inlet where the air pressure is necessarily greater.

The length, width, and height dimensions of the overall air handling fixture are designated respectively by the letters L, W, and d in the drawings. The sides incorporating the inlet and outlet openings and elongated slots are always at least as long as the remaining opposite sides. Thus, while a square configuration has been illustrated in the drawings, other quadralateral shapes such as rectangular may be provided. In the event of such a rectangular configuration, the inlet and outlet openings and slots would preferably be incorporated in the long sides.

OPERATION In the preferred embodiment of the invention as described in FIGS. 1 to 4, the air handling lighting fixture casing is preferably a square configuration having width and length dimensions of 36 inches and an overall height of 6 inches. These dimensions will accommodate 4 U-shaped fluorescent lamps of approximately 160 watts each. The air handling capability where a single fixture is used for supply or return only is 200 cubic feet per minute. In the event a single fixture is used both for supply and return, the air handling capability would be lOO cubic feet per minute. This airflow takes place all with less than 0.2 inches of water pressure loss. In the case of the four fluorescent tube configuration shown, the heat reclamation or rejection capability is approximately 420 B.t.u. per hour.

The fixture dimensioned as described, will readily fit standard T-bar ceiling installations or other ceiling suspension systems within the ceiling cavity area. Thus, the side flange 11 will seat on the T-bars illustrated in phantom lines in FIG. 1 so that the unit is supported with its bottom substantially flush with the ceiling. The airflow ducting in the ceiling may be of circular, square, or rectangular cross section it only being necessary to modify the end to conform to the geometry of the inlet and outlet 13 and 14. Since the overall dimension is minimal, the installation of the air handling and lighting fixture and connection to ceiling ducts is greatly simplified as compared to the installation of prior art structures.

As described, if the fixture is to be used as both an air supply and air return, the air supply or inlet will be passed through the air passage 27 described in FIG. 3 and out of the slot 19 into the office or room. Return air will then pass up the corresponding slot 20 on the opposite side of the unit to the outlet 14 and connecting duct 16 of FIG. ll.

When the fixture is used solely as an air supply or an air return, both passages will receive inlet air or outlet air as the case may be.

With the damper in its solid line position illustrated in FIG. 3, maximum air passage openings are provided in the air passage means for maximum air circulation. Under this condition, the air passage and air slot are of sufficient dimensions to accommodate the airflow without any whistling effects. When the damper is lowered as illustrated in FIG. 3 towards the dotted line position, the available air passage becomes restricted. However, because of the geometry of the damper; that is, its tapered configuration, the restriction of the air passage is such as to maintain the heretofore described uniform air velocity profile from the slot so that portions of the airstream do not attain velocities sufficiently high to result in any annoying whistling sound.

Finally, and as mentioned heretofore, dissipation of heat from the ballast is readily effected through the thermal conductive contact of the metallic casing portions supporting the ballast with the walls of the air passages.

From the foregoing, it will be evident that the present invention has provided a greatly improved air handling lighting fixture combination wherein problems heretofore encountered with prior art devices have been substantially eliminated.

What is claimed is:

1. An air handling lighting fixture comprising, in combination:

a. a casing incorporating fluorescent light tubes, said casing including air passage means having one end terminating at a side opening centrally located in the casing and its other end opening out in an elongated slot defined by a marginal bottom portion of the casing, said slot being longer than said side opening; and

b. a damper member in said air passage means elongated in the direction of said slot and tapering in width from its central portion towards its ends to define an increased area air passage in said passage means at points further from the central portion of said slot communicating with said side opening than at points closer to the central portion of said slot so that air passing through said air passage is distributed from said slot with a substantially uniform air velocity profile over the length of said slot.

2. A fixture according to claim 1, in which said damper member is pivoted to a side of said air passage means for swinging movement from a position substantially parallel to airflow to a position substantially normal to airflow whereby the volume of air passing through said air passage may be adjustable by the pivoting of said damper.

3. An air handling lighting fixture for mounting within the cavity area of a suspended ceiling installation of given depth dimension comprising, in combination:

a. a casing structure having a marginal flange for seating on at least portions of said suspended ceiling installation and having an overall height less than said given depth;

b. inlet and outlet openings elongated in horizontal directions to minimize their vertical dimensions for a given opening area, said openings being formed at central portions in opposite sides of said casing for connection to air handling ceiling ducts in said cavity area, said casing defining elongated bottom air inlet and outlet slots adjacent to said opposite sides, and including air passage means connecting said slots respectively with said inlet and outlet openings;

c. a damper means ineach of said air passage means, each damper means being elongated in the direction of its associated slot and tapering in cross-sectional area from its central portion towards its end portions to define in the air passage means an elongated air passage increasing in cross section towards its ends so that air centrally admitted through the inlet opening is distributed to pass out of the associated inlet air slot with a substantially uniform velocity profile and air passed up through the outlet air slot and associated outlet opening is uniformly received and collimated; and

d. fluorescent lighting tubes disposed in said casing between said passage means for directing light out of the bottom of said casing.

4. A fixture according to claim 3, in which the length of said opposite sides is at least four times the height of said casing. said elongated bottom slot running substantially the full length of said opposite sides.

5. A fixture according to claim 3, in which said damper is varied.

6. A fixture according to claim 3, including ballast means for said lighting tubes disposed in thermally conductive contact with portions of said casing in thermal engagement with the walls of said passage means so that cooling of said ballast means is effected by airflow through said passage means.

7. A fixture according to claim3, in which said casing is of quadralateral shape, said opposite sides being of equal length and at least as long as the remaining sides. 

1. An air handling lighting fixture comprising, in combination: a. a casing incorporating fluorescent light tubes, said casing including air passage means having one end terminating at a side opening centrally located in the casing and its other end opening out in an elongated slot defined by a marginal bottom portion of the casing, said slot being longer than said side opening; and b. a damper member in said air passage means elongated in the direction of said slOt and tapering in width from its central portion towards its ends to define an increased area air passage in said passage means at points further from the central portion of said slot communicating with said side opening than at points closer to the central portion of said slot so that air passing through said air passage is distributed from said slot with a substantially uniform air velocity profile over the length of said slot.
 2. A fixture according to claim 1, in which said damper member is pivoted to a side of said air passage means for swinging movement from a position substantially parallel to airflow to a position substantially normal to airflow whereby the volume of air passing through said air passage may be adjustable by the pivoting of said damper.
 3. An air handling lighting fixture for mounting within the cavity area of a suspended ceiling installation of given depth dimension comprising, in combination: a. a casing structure having a marginal flange for seating on at least portions of said suspended ceiling installation and having an overall height less than said given depth; b. inlet and outlet openings elongated in horizontal directions to minimize their vertical dimensions for a given opening area, said openings being formed at central portions in opposite sides of said casing for connection to air handling ceiling ducts in said cavity area, said casing defining elongated bottom air inlet and outlet slots adjacent to said opposite sides, and including air passage means connecting said slots respectively with said inlet and outlet openings; c. a damper means in each of said air passage means, each damper means being elongated in the direction of its associated slot and tapering in cross-sectional area from its central portion towards its end portions to define in the air passage means an elongated air passage increasing in cross section towards its ends so that air centrally admitted through the inlet opening is distributed to pass out of the associated inlet air slot with a substantially uniform velocity profile and air passed up through the outlet air slot and associated outlet opening is uniformly received and collimated; and d. fluorescent lighting tubes disposed in said casing between said passage means for directing light out of the bottom of said casing.
 4. A fixture according to claim 3, in which the length of said opposite sides is at least four times the height of said casing, said elongated bottom slot running substantially the full length of said opposite sides.
 5. A fixture according to claim 3, in which said damper is pivotally mounted to a side of said passage means so that the total cross section area of said elongated air passage can be varied.
 6. A fixture according to claim 3, including ballast means for said lighting tubes disposed in thermally conductive contact with portions of said casing in thermal engagement with the walls of said passage means so that cooling of said ballast means is effected by airflow through said passage means.
 7. A fixture according to claim 3, in which said casing is of quadralateral shape, said opposite sides being of equal length and at least as long as the remaining sides. 